Process for electrolytically removing tarnish from silver articles



March 24, 1953 BRANNAN 2,632,730

PROCESS FOR ELECTROLYTICALLY REMOVING TARNISH FROM SILVER ARTICLES Filed April 29, 1950 2 Sl-lEETS-SHEET 1 IN VEN TOR. 1e 6 3574/1/44.

March 24, 1953 Fiied April 29, 1950 L. BRA PROCESS FOR ELECTROLYTICALLY REMOVING TARNISH FROM SILVER ARTICLES NNAN 2 SHEETS-SHEET 2 INVENTOR. 4 5/4/1/1 11- Patented Mar. 24, 1953 The present -invention relates to a machine,

method and solution for removing tarnish-"from silverarticles by galvanic action.

It isone "ofthe objects ofthis invention toprovide an apparatus and methodforcleaningand polishing 'silver'articles or articles having a silvered surface which electrolytically removes all the'tarni'sh from the articles and simultaneously polishes and purifies so that-the surfaces are'rendered electrolytically clean and sanitary.

I "A"further objective of this invention is to provide amachine which'functions both as an" outer will be specifically pointed out or will become apparent as the description proceeds.

. In accordance with this invention, tarnished I :silver articles may be eliiciently cleaned and pol- ;ished byimmer'sing the same in an aqueous solution'containing suitable quantities of salt and soap when positioned within a rotatable zinc container or drum. It has been found that the tarnish on silver is removed by galvanic action upon merely immersing the silver articles in the solution when the silver article is in direct contact with the zinc surface. It has also been found, however, that a more highly polished surface results from rotating the zinc drum due to the polishing action of soft globules or pellets of soap which are present in the brine solution. Furthermore, the abrasive action between the silver article and the zinc surface is sufiicient to continuously maintain the interior zinc surface free from extraneous materials including oxides which enables the drum to be used at high efficiency over a long period of time before cleaning is necessary.

A solution which is found to be particularly satisfactory for accomplishing the foregoing objects is a salt solution in which soap is insoluble, and in which the soap forms globules or pellets upon being added to the salt solution. A solution of this type which has been successfully used is comprised of 4 tablespoons of salt and 4 tablespoons of granulated or chip soap to one gallon of Water. The salt may be ordinary table salt, that is sodium chloride. This solution in the zinc drum acts as an electrolyte when tarnished silver articles are placed in the solution in contact with .12 the zinc surface. While it is not desiredi-tolbe bound by theory, itis believed that the iiarfiish "remcval is effected through the p'r-i nciple cl pperationfot a voltaic cell. -I-tis thought-that the Zinc 9 provides the outer casingcfavoltaic primary cell of-which the silver becomes the positive l pole and the zinc the negative pole and the water salt soap solution serving as electrolyte. *Hydrog'en is formed at the surface'of the silver reducing the 10 sumson the surfacecfth ilve' acemes-nee goes intothesolutionat the negativa-po form. of zinc-ions. The liberatrfhydrogen is their thought to";coinb'ir-ieiyit-li the vvate'r of the "bath to form weaksulfuric' acid.-

In the drawings Figure 1 is a"perspective"view cf -theap aratus of this invention "havingthe cover the-open position;

Figure'Z is a side viewer the apparatuscfFigure 1;

' Figure 3 is a "crosssection'takenalongline 3 3 'of' Fi'gurel; and,

V Figure 4: is an end view' of the apparatus cf this invention.

"There 1 is provided at I a drum tumbler cream tainen'whic'hconsists'of "'a""cylin'drical section In and end portions lb and la. The cylindrical portion la is provided with a longitudinally dis- 3() posed opening on the periphery thereof for the purpose of allowin the drum to be loaded and unloaded. A cover or closure section 2 is provided and hinged at 3 and adapted to provide an air and gas-tight seal for the opening. Cover 2 may be provided with a rubber gasket 4, the compression of which, on closing provides the desired seal.

A peripheral bead 5 is integrally attached to the inner edges of the opening and projects inwardly 40 therefrom to provide a surface against which cover 2 and its gasket 4 is compressed upon closing. Bead 5 is supported by a turnplate II to insure a rigid connection with cylindrical por-. tion la.

Cam fasteners 6 are integrally attached to cover 2 and are adapted to engage lugs or strikes 1 which are mounted on cylindrical portion la. Closure of cover 2 is accomplished by engaging lug 1 with fasteners 6 and depressing the handle portion 6a to depress cover 2 and rubber gasket 4 into contact with bead 5 to effect a seal, thereby preventing the escape of gas or liquid from the drum l during rotation.

Drum I is provided with centrally located threaded flanges 8 oppositely disposed on end POI-v tions it and I for receiving threaded studs 9 and I9. Stud 9 is bent to form a hand crank which when threaded into flange 8 renders drum I and stud 9 an integral unit so that rotation of stud 9 causes the rotation of drum 1. Studs 9 and ID are suitably journaled for rotation in bearings M to enable the smooth rotation of the drum l within frame end support members I2 and I3.

Frame ends I2 and I3 are triangular in shape and have their edges bent to increase their strength. To insure against wobbling, there is provided at l5 a suitable bracing member positioned between end members I2 and I3 and rigidly attached thereto.

To enable drum l to be held in a stationary position during the loading and unloading operation, there is provided at I! an eyeslot integrally attached to crank 9 and a suitable latch member I'IA the base portion of which is attached to end member l2.

Silver articles of various shapes may be cleaned and simultaneously burnished by placing the same in the heretofore described apparatus containing the electrolyte of thi invention by securing. the cover and rotating the handle a few times.

The beneficial effects are obtained from the use of a solution containing ordinary laundry soaps. Most detergents or dishwashing combinations, however, have been found to be soluble in a brine solution and for this reason are not recommended. On rotation, the soft globules or pellets of soap act as a polisher of the silverware during the rotation of the drum, thereby increasing the shine and luster of the cleaned article.

For practical reasons the exterior surface of drum I has been plated with nickel or nickel and copper to protect the same against corrosion and to increase the attractiveness of the apparatus. Furthermore it is believed that the presence of the nickel coating reduces the rate of zinc deterioration both internally and externally and for that reason greatly prolongs the life of the apparatus.

To summarize, this invention provides a rotatable voltaic cell battery and a method and solution for using the same to remove tarnish from silver articles in a simple, inexpensive and positive manner; the voltaic cell battery consists of a hollow cylindrical shaped zinc drum having therein an aqueous brine solution containing soap globules or pellets and silver positioned in the solution.

What is claimed is:

1. A process for cleaning silver articles by galvanic action which comprises agitating silver articles in contact with the interior of a rotating zinc drum, said drum containing a solution consisting of water, salt and soap, the said soap being insoluble and present in the form of globules, whereby tarnish is removed from the said silver by galvanic action and burnished by contact with the said soa globules.

2. A process for cleaning silver articles by galvanic action which comprises agitating silver articles in contact with the interior of a rotating zinc drum, said drum containing an aqueous solution having the proportions of 4 tablespoons of sodium chloride and 4 tablespoons of soap to each gallon of water whereby tarnish is removed from the said silver by galvanic action.

3. A process for electrolytically removing tarnish from silver articles which comprises immersing silver articles in an aqueous solution in a zinc drum, the essential constituents of said solution being sodium chloride and soap in the proportions of 4 tablespoons of sodium chloride and 4 tablespoons of soap to each gallon of water, and agitating said articles in said solution in contact with said zinc drum.

LEE BRANNAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 293,528 Scribner Feb. 12, 1884 1,035,633 Phillips Aug. 13, 1912 1,068,568 Couch July 29, 1913 1,139,683 Keyt May 18, 1915 1,601,511 Schmutz Sept. 28, 1926 1,983,401 Robinson Dec. 4, 1934 

1. A PROCESS FOR CLEANING SILVER ARTICLES BY GALVANIC ACTION WHICH COMPRISES AGITATING SILVER ARTICLES IN CONTACT WITH THE INTERIOR OF A ROTATING ZINC DRUM, SAID DRUM CONTAINING A SOLUTION CONSISTING OF WATER, SALT AND SOAP, THE SAID SOAP BEING INSOLUBLE AND PRESENT IN THE FORM OF GLOBULES, WHEREBY TARNISH IS REMOVED FROM THE SAID SILVER BY GALVANIC ACTION AND BURNISHED BY CONTACT WITH THE SAID SOAP GLOBULES. 